Publications

18 Publications matching the given criteria: (Clear all filters)
Project: LIFE Adult18

Abstract (Expand)

Background: The blood transcriptome is expected to provide a detailed picture of an organism's physiological state with potential outcomes for applications in medical diagnostics and molecular and epidemiological research. We here present the analysis of blood specimens of 3,388 adult individuals, together with phenotype characteristics such as disease history, medication status, lifestyle factors, and body mass index (BMI). The size and heterogeneity of this data challenges analytics in terms of dimension reduction, knowledge mining, feature extraction, and data integration. Methods: Self-organizing maps (SOM)-machine learning was applied to study transcriptional states on a population-wide scale. This method permits a detailed description and visualization of the molecular heterogeneity of transcriptomes and of their association with different phenotypic features. Results: The diversity of transcriptomes is described by personalized SOM-portraits, which specify the samples in terms of modules of co-expressed genes of different functional context. We identified two major blood transcriptome types where type 1 was found more in men, the elderly, and overweight people and it upregulated genes associated with inflammation and increased heme metabolism, while type 2 was predominantly found in women, younger, and normal weight participants and it was associated with activated immune responses, transcriptional, ribosomal, mitochondrial, and telomere-maintenance cell-functions. We find a striking overlap of signatures shared by multiple diseases, aging, and obesity driven by an underlying common pattern, which was associated with the immune response and the increase of inflammatory processes. Conclusions: Machine learning applications for large and heterogeneous omics data provide a holistic view on the diversity of the human blood transcriptome. It provides a tool for comparative analyses of transcriptional signatures and of associated phenotypes in population studies and medical applications.

Authors: M. Schmidt, L. Hopp, A. Arakelyan, H. Kirsten, C. Engel, K. Wirkner, K. Krohn, R. Burkhardt, J. Thiery, M. Loeffler, H. Loeffler-Wirth, H. Binder

Date Published: 11th Mar 2021

Publication Type: Journal article

Abstract (Expand)

Background The pathophysiology of arterial stiffness is not completely understood. Pulse wave velocity (PWV) is an established marker for arterial stiffness. We compare genetics of three PWV modes, namely carotid-femoral PWV (cfPWV), brachial-ankle (baPWV) and brachial-femoral (bfPWV), reflecting different vascular segments to analyse association with genetic variants, heritability and genetic correlation with other biological traits. Furthermore we searched for shared genetic architecture concerning PWV, blood pressure (BP) and coronary artery disease (CAD) and examined the causal relationship between PWV and BP. Methods and results We performed a genome-wide association study (GWAS) for cfPWV, baPWV and bfPWV in LIFE-Adult (N = 3,643–6,734). We analysed the overlap of detected genetic loci with those of BP and CAD and performed genetic correlation analyses. By bidirectional Mendelian Randomization, we assessed the causal relationships between PWV and BP. For cfPWV we identified a new locus with genome-wide significance near SLC4A7 on cytoband 3p24.1 (lead SNP rs939834: p = 2.05x10-8). We replicated a known PWV locus on cytoband 14q32.2 near RP11-61O1.1 (lead SNPs: rs17773233, p = 1.38x10-4; rs1381289, p = 1.91x10-4) For baPWV we estimated a heritability of 28% and significant genetic correlation with hypertension (rg = 0.27, p = 6.65x10-8). We showed a positive causal effect of systolic blood pressure on PWV modes (cfPWV: p = 1.51x10-4; bfPWV: p = 1.45x10-3; baPWV: p = 6.82x10-15). Conclusions We identified a new locus for arterial stiffness and successfully replicated an earlier proposed locus. PWV shares common genetic architecture with BP and CAD. BP causally affects PWV. Larger studies are required to further unravel the genetic determinants and effects of PWV.

Authors: Michael Rode, Andrej Teren, Kerstin Wirkner, Katrin Horn, Holger Kirsten, Markus Loeffler, Markus Scholz, Janne Pott

Date Published: 13th Aug 2020

Publication Type: Journal article

Human Diseases: arteriosclerosis, arteriosclerotic cardiovascular disease

Abstract (Expand)

Purpose: The onset and progression of optic neuropathies like glaucoma often occurs asymmetrically between the two eyes of a patient. Interocular circumpapillary retinal nerve fiber layer thickness (cpRNFLT) differences could detect disease earlier. To apply such differences diagnostically, detailed location specific norms are necessary. Methods: Spectral-domain optical coherence tomography cpRNFLT circle scans from the population-based Leipzig Research Centre for Civilization Diseases–Adult study were selected. At each of the 768 radial scanning locations, normative interocular cpRNFLT difference distributions were calculated based on age and interocular radius difference. Results: A total of 8966 cpRNFLT scans of healthy eyes (4483 patients; 55% female; age range, 20–79 years) were selected. Global cpRNFLT average was 1.53 µm thicker in right eyes (P < 2.2 × 10–16). On 96% of the 768 locations, left minus right eye differences were significant (P < 0.05), varying between +11.6 µm (superonasal location) and −11.8 µm (nasal location). Increased age and difference in interocular scanning radii were associated with an increased mean and variance of interocular cpRNFLT difference at most retinal locations, apart from the area temporal to the inferior RNF bundle where cpRNFLT becomes more similar between eyes with age. Conclusions: We provide pointwise normative distributions of interocular cpRNFLT differences at an unprecedentedly high spatial resolution of 768 A-scans and reveal considerable location specific asymmetries as well as their associations with age and scanning radius differences between eyes. Translational Relevance: To facilitate clinical application, we implement these age- and radius-specific norms across all 768 locations in an open-source software to generate patient-specific normative color plots.

Authors: Neda Baniasadi, Franziska G. Rauscher, Dian Li, Mengyu Wang, Eun Young Choi, Hui Wang, Thomas Peschel, Kerstin Wirkner, Toralf Kirsten, Joachim Thiery, Christoph Engel, Markus Loeffler, Tobias Elze

Date Published: 3rd Aug 2020

Publication Type: Journal article

Abstract (Expand)

Body shape and composition are heterogeneous among humans with possible impact for health. Anthropometric methods and data are needed to better describe the diversity of the human body in human populations, its age dependence, and associations with health risk. We applied whole-body laser scanning to a cohort of 8499 women and men of age 40-80 years within the frame of the LIFE (Leipzig Research Center for Civilization Diseases) study aimed at discovering health risk in a middle European urban population. Body scanning delivers multidimensional anthropometric data, which were further processed by machine learning to stratify the participants into body types. We here applied this body typing concept to describe the diversity of body shapes in an aging population and its association with physical activity and selected health and lifestyle factors. We find that aging results in similar reshaping of female and male bodies despite the large diversity of body types observed in the study. Slim body shapes remain slim and partly tend to become even more lean and fragile, while obese body shapes remain obese. Female body shapes change more strongly than male ones. The incidence of the different body types changes with characteristic Life Course trajectories. Physical activity is inversely related to the body mass index and decreases with age, while self-reported incidence for myocardial infarction shows overall the inverse trend. We discuss health risks factors in the context of body shape and its relation to obesity. Body typing opens options for personalized anthropometry to better estimate health risk in epidemiological research and future clinical applications.

Authors: A. Frenzel, H. Binder, N. Walter, K. Wirkner, M. Loeffler, H. Loeffler-Wirth

Date Published: 29th Mar 2020

Publication Type: Not specified

Abstract (Expand)

PURPOSE: To investigate the role of sex on retinal nerve fiber layer (RNFL) thickness at 768 circumpapillary locations based on OCT findings. DESIGN: Population-based cross-sectional study. PARTICIPANTS: We investigated 5646 eyes of 5646 healthy participants from the Leipzig Research Centre for Civilization Diseases (LIFE)-Adult Study of a predominantly white population. METHODS: All participants underwent standardized systemic assessments and ocular imaging. Circumpapillary RNFL (cRNFL) thickness was measured at 768 points equidistant from the optic nerve head using spectral-domain OCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany). To control ocular magnification effects, the true scanning radius was estimated by scanning focus. Student t test was used to evaluate sex differences in cRNFL thickness globally and at each of the 768 locations. Multivariable linear regression and analysis of variance were used to evaluate individual contributions of various factors to cRNFL thickness variance. MAIN OUTCOME MEASURES: Difference in cRNFL thickness between males and females. RESULTS: Our population consisted of 54.8% females. The global cRNFL thickness was 1 mum thicker in females (P < 0.001). However, detailed analysis at each of the 768 locations revealed substantial location specificity of the sex effects, with RNFL thickness difference ranging from -9.98 to +8.00 mum. Females showed significantly thicker RNFLs in the temporal, superotemporal, nasal, inferonasal, and inferotemporal regions (43.6% of 768 locations), whereas males showed significantly thicker RNFLs in the superior region (13.2%). The results were similar after adjusting for age, body height, and scanning radius. The superotemporal and inferotemporal RNFL peaks shifted temporally in females by 2.4 degrees and 1.9 degrees , respectively. On regions with significant sex effects, sex explained more RNFL thickness variance than age, whereas the major peak locations and interpeak angle explained most of the RNFL thickness variance unexplained by sex. CONCLUSIONS: Substantial sex effects on cRNFL thickness were found at 56.8% of all 768 circumpapillary locations, with specific patterns for different sectors. Over large regions, sex was at least as important in explaining the cRNFL thickness variance as was age, which is well established to have a substantial impact on cRNFL thickness. Including sex in the cRNFL thickness norm could therefore improve glaucoma diagnosis and monitoring.

Authors: D. Li, F. G. Rauscher, E. Y. Choi, M. Wang, N. Baniasadi, K. Wirkner, T. Kirsten, J. Thiery, C. Engel, M. Loeffler, T. Elze

Date Published: 17th Nov 2019

Publication Type: Journal article

Abstract (Expand)

BACKGROUND: Studies in older adults or those with cognitive impairment have shown associations between cognitive and olfactory performance, but there are few population-based studies especially in younger adults. We therefore cross-sectionally analyzed this association using data from the population-based LIFE-Adult-Study. METHODS: Cognitive assessments comprised tests from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD): verbal fluency (VF), word list learning and recall (WLL, WLR), and the Trail Making Tests (TMT) A and B. The "Sniffin' Sticks Screening 12" test was used to measure olfactory performance. Linear regression analyses were performed to determine associations between the number of correctly identified odors (0 to 12) and the five cognitive test scores, adjusted for sex, age, education, and the presence of depressive symptoms. Receiver operating characteristic (ROC) analysis was carried out to determine the discriminative performance of the number of correctly identified odors regarding identification of cognition impairment. RESULTS: A total of 6783 participants (51.3% female) completed the olfaction test and the VF test and TMT. A subgroup of 2227 participants (46.9% female) also completed the WLL and WLR tests. Based on age-, sex-, and education-specific norms from CERAD, the following numbers of participants were considered cognitively impaired: VF 759 (11.2%), WLL 242 (10.9%), WLR: 132 (5.9%), TMT-A 415 (6.1%), and TMT-B/A ratio 677 (10.0%). On average, score values for VF were higher by 0.42 points (p < 0.001), for WLL higher by 0.32 points (p = 0.001), for WLR higher by 0.31 points (p = 0.002), for TMT-A lower by 0.25 points (p < 0.001), and for TMT-B/A ratio lower by 0.01 points (p < 0.001) per number of correctly identified odors. ROC analysis revealed area under the curve values from 0.55 to 0.62 for the five cognitive tests. CONCLUSIONS: Better olfactory performance was associated with better cognitive performance in all five tests in adults - adjusted for age, sex, education, and the presence of depressive symptoms. However, the ability of the smell test to discriminate between individuals with and without cognitive impairment was limited. The value of olfactory testing in early screening for cognitive impairment should be investigated in longitudinal studies.

Authors: M. Yahiaoui-Doktor, T. Luck, S. G. Riedel-Heller, M. Loeffler, K. Wirkner, C. Engel

Date Published: 10th May 2019

Publication Type: Not specified

Human Diseases: Alzheimer's disease

Abstract (Expand)

Aims: Diabetes screening strategies using glycated haemoglobin (HbA1c) as first-instance diagnostic parameter may cause failure to detect individuals with abnormal glucose regulation and possible signs of microvascular complications despite "rule-out" HbA1c levels. This cross-sectional study examined the diagnostic performance of HbA1c in relation to fasting and two-hour postload plasma glucose (FPG/2 h-PG), and investigated whether individuals with normal HbA1c but abnormal FPG/2 h-PG have a higher prevalence of moderately increased albuminuria as possible sign of early stage kidney damage. Methods: A total of 2695 individuals (age 40-79 years, 48% men) without prior diagnosis of diabetes and complete measurement of HbA1c, FPG, 2 h-PG and urine albumin-creatinine ratio (UACR) were taken from a large population-based epidemiological study in the City of Leipzig, Germany. Results: A total of 2439 individuals (90.5%, 95% CI: 89.4-91.6) had normal HbA1c levels, <39 mmol/mol (<5.7%), while 234 (8.7%, 95% CI: 7.7-9.8) had prediabetes, HbA1c >/=39 and <48 mmol/mol (>/=5.7 and <6.5%), and 22 (0.8%, 95% CI: 0.5-1.2) had diabetes, HbA1c >/=48 mmol/mol (>/=6.5%), according to HbA1c. Among individuals with normal HbA1c, 35.6% (95% CI: 33.7-37.5) had impaired fasting glucose or impaired glucose tolerance and 1.8% (95% CI: 1.4-2.4) had diabetes according to FPG/2 h-PG. Individuals with normal HbA1c but prediabetic or diabetic FPG/2 h-PG had a significantly higher prevalence of moderately increased albuminuria (9.4%, 95% CI: 7.6-11.5 and 13.3%, 95% CI: 5.8-25.4, respectively) than individuals with normal HbA1c and normal FPG/2 h-PG (3.9%, 95% CI: 3.0-5.0). Conclusions: The prevalence of prediabetes according to FPG/2 h-PG among individuals with normal HbA1c is considerably high, and the prevalence of moderately increased albuminuria in this group is significantly elevated. Risk factors for diabetes such as age, gender and BMI may help to better identify this at-risk group.

Authors: M. Zivkovic, A. Tonjes, R. Baber, K. Wirkner, M. Loeffler, C. Engel

Date Published: 1st Mar 2019

Publication Type: Not specified

Human Diseases: glucose metabolism disease

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